Allegheny County Reports Second Case of Measles in 2026

Published on October 09, 2026

PITTSBURGH – The Allegheny County Health Department (ACHD) was informed of a second resident who tested positive for measles.

ACHD immediately began a case investigation and contact tracing. The two cases are connected because both people went to the same school. They do not live in the same household, which suggests there was likely a previously unknown exposure at the school.

ACHD is working to determine how the individuals were infected, whether anyone else may have been exposed, and whether there are additional cases.

“This connection significantly expands our investigation,” said Dr. Jillian Irwin, Allegheny County Health Department Medical Director. “Determining how these individuals were infected and the details of all additional exposures is key to successfully stopping further spread”

As part of its investigation, ACHD will call or text people who were exposed to the individuals while they were infectious. As part of those conversations, ACHD will provide information on how to reduce the likelihood of getting or spreading measles.

ACHD recommends that anyone who is due for measles (MMR) vaccination contact their health care provider to receive the vaccine. Given the two confirmed cases in Allegheny County, ACHD is also recommending that health care providers administer the measles, mumps and rubella (MMR) vaccine on an accelerated schedule to patients ages six months and older to help protect against measles.

ACHD will update confirmed measles counts daily as needed on AlleghenyCounty.US/Measles. The department does not plan to issue an individual news release for every additional confirmed case and will instead provide ongoing updates on its website.

The Pennsylvania Department of Health will also be updating measles counts on its statewide dashboard. Case counts on the county and state websites may differ temporarily because the sites may be updated at different times.

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The Allegheny County Health Department's mission is to protect, promote, and preserve the health and well-being of the more than 1.2 million people who call Allegheny County home.

Media inquiries may be directed to Ronnie Das, Public Information Officer for the Health Department, at ronnie.das@alleghenycounty.us or by phone at 412-578-7991.